This invention relates to a shutter speed display device for use in an electric shutter operating circuit of a photographic camera.
Recently, it has been proposed to use luminous diodes or liquid crystal elements for displaying the shutter speed of a photographic camera. In such shutter speed display devices, in order to detect the level of a signal utilized to display the shutter speed, it is necessary to increase the magnitude of the input signal from a sensor to a degree sufficient to nullify the effect of deviations of the characteristics of various elements utilized in the shutter speed display device from prescribed characteristics. To this end it is necessary to amplify the input signal. In order to construct an amplifier that will operate at a constant amplification factor even if the voltage of the supply source or ambient temperature varies. Therefore, it has been necessary to use a complicated circuit.